1. Field of the Invention
This invention relates generally to a cutting apparatus. More particularly, but not by way of limitation, the present invention relates to a method and apparatus for removing a fitting from a pipe.
2. Brief Description of the Related Art
A number of prior art devices have been suggested for removing a fitting from a pipe. However, these devices suffer from a number of limitations and deficiencies. One such device is disclosed in U.S. Pat. No. 6,929,430, issued to Dever. Dever discloses a water closet flange removal tool that includes an axial shaft, a cylindrical guide body attached to a lower end of the shaft, and a cylindrical wall cutter mounted above the guide body and on the axial shaft. The Dever tool uses a single component wherein the cylindrical guide body is intended to guide the cylindrical wall cutter along the interior surface of the pipe to thereby position the cylindrical wall cutter along the outside of the pipe to remove the fitting.
However, the Dever tool suffers from a number of problems with the design and operation thereof. For example, the diameter of the cylindrical guide body is fixed such that it can only be used with a pipe having a specific diameter. The cylindrical guide body cannot be adjusted to fit properly in a number of different pipes having different diameters. Using the Dever tool to remove a fitting from a pipe having an inside diameter that varies because of, for example, differences in manufacturing tolerances, wear and tear associated with normal use, or the like, would limit the accuracy or reliability of the Dever tool. For example, if the Dever tool were to be used to remove the fitting from a pipe wherein the interior dimension of the pipe had been expanded through normal wear and tear and differing manufacturing tolerances, the cylindrical guide body would not form a secure fit within the interior pipe wall and there may be sufficient room within the pipe for the cylindrical guide body to move laterally with respect to the central axis of the pipe. As would be understood, in this situation, the excess movement of the cylindrical guide body within the interior of the pipe would result in the cylindrical wall cutter being misaligned with the central axis of the pipe. In such a case, the cylindrical wall cutter would likely contact the pipe, thereby destroying or otherwise damaging the pipe.
In addition, the Dever tool could not be used with a pipe that has an interior dimension smaller than specified due to, for example, different manufacturing tolerances and/or obstructions within the pipe. In such a situation where the interior dimension of the pipe is less than that of the outer dimension of the cylindrical guide body, Devers cylindrical guide body would be too large to be inserted into the pipe and thereby could not be used at all.
Another limitation of the Dever tool is the cylindrical guide body and cylindrical wall cutter being axially attached to a single rod. As would be understood in the art, an individual using the Dever tool with, for example, a drill, wherein the individual did not maintain substantially perfect alignment of the rod axis with the central axis of the pipe could thereby twist and alter the angle where the cylindrical wall cutter contacts the pipe and/or the fitting. In this instance, the cylindrical wall cutter could likely contact the pipe in addition to the fitting, thereby causing damage to the pipe. That is, an individual using the Dever tool would be required to maintain almost perfect alignment throughout the operation of the system to prevent damage to the pipe. In the instant described above wherein the interior dimension of the pipe was enlarged such that the cylindrical guide body did not maintain a consistent fit, the individual using the Dever tool could more likely misalign the single rod with the central axis of the pipe and thereby damage or destroy the pipe.
Yet another limitation of the Dever tool is presented wherein the interior of the pipe is blocked or configured such that the cylindrical guide body could not be extended downward therein for the length necessary for the cylindrical wall cutter to remove the exterior fitting. That is, because the Dever tool relies on the cylindrical wall cutter and the cylindrical guide body to be fixed on the axial rod, in an instance where the interior of the pipe is obstructed or is configured, for example, with an elbow positioned near the entrance to the pipe, the user would not be able to extend the cylindrical guide body into the pipe a sufficient length for the cylindrical wall cutter to remove the fitting.
Thus, the Dever system suffers from a number of limitations wherein it could not be used for certain configurations of a pipe and/or it could not be used in a situation in which the interior dimension of the pipe was larger than the exterior diameter of the cylindrical guide body.
To this end, a need exists for an improved apparatus and method for removing a fitting from a pipe with minimal or no damage to the pipe. It is to such an apparatus and method that the present invention is directed.